Cutter manufacture



April 1944- M. B. MENTLEY ET AL ,3 5,9

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet l INVENTORS MAX B. MENTLEY W, MMMIVW ATTORNEYS April 4- M. B. MENTLEY ET AL 2,345,986

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet 2 ATTORNEYS April 1944- M. B. MENTLEY ET AL 2,345,986

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet 3 INVENTORS MAX 5. MENTLEY y I DONALD 0. AUSTIN WYM ATTORN YS April 1944- M. B. MENTLEY ET AL 2,345,986

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet 4 I NV EN TORS FIG.6- MAX B. MENTLEY BY v DONALD D. AUSTIN mm awdwke/do ATTORNEYS April 1944- M. B.- MENTLEY ET AL 2,345,986

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet 5 FIG. 9.

' INVENTORS MAX 8. MENTLEY By DONALD D. AUSTIN J Wt ATTORNEYS April M. B. MENTLEY ET AL 2,345,986

CUTTER MANUFACTURE Filed May 9, 1941 6 Sheets-Sheet 6 I I92 l o/uoo 1 $0 FIGJZ.

' INVENTORS MAX B. MENTLEY BY DONALD D. AUSTIN A TTORNEYS Patented Apr. 4, 1944 co'r'rna monomer.

Max B. Mentley and Donald D. Austin, Detroit,

Mich., assignors to National Broacli & Machine Company, Detroit, Mich., a corporation of Michigan Application May 9, 1941, Serial No. 392,790

18 Claims.

The present invention relates to a grinding machine and more particularly to a machine adapted to grind milling cutters.

Due to its flexibility, the present machine may properly be regarded as an all-purpose grinding machine, but it will be explained with particular reference to the grinding of milling cutters, either bevel or cylindrical.

It is an object of the present invention to provide a grinding machine in which the grinder is adjustable vertically and angularly about a vertical axis, and in which the work spindle is adjustable horizontally toward and away from the grindin spindle, and is adjustable angularly about a horizontal axis perpendicular to the axis Figure 10 is a section on the line l--l0, Figure 9.

of the work spindle, and is mounted for traverse in a horizontal plane.

It is a further object of the present invention to provide a grinder having a grinder spindle support mounted for angular adjustment, and movable trimming mechanism mounted directl on said support.

It is a further object of the present invention to provide, in a machine of the class described, a work spindle of novel characteristics.

More particularly, it is a further object of the present invention to provide a work spindle mounted for traverse in combination with generating means for rotating said spindle in accordance with its traverse, in combination with a coil spring biasing said spindle in one direction.

It is a further object of the present invention to provide a work supporting spindle having novel clamping indexing means.

Other objects of the invention will be apparent as the description proceeds, and when taken in conjunction with the accompanying drawings, wherein: I

Figure 1 is a perspective of the complete grinding machine;

Figure 2 is a fragmentary vertical section illustrating vertical adjustment of the cutter spin die;

Figures 3 and 4 are fragmentary side elevations of the grinder spindle showing the same in two different positions;

Figure 5 is a detail elevation of the work spindle, with parts broken away;

Figure 6' is a fragmentary plan view of part of the sine bar mechanism;

Figure '7 is a side elevation of the structure shown in Figure 6, with parts broken away;

Figure 8 is a section on the line 8-8, Figure '7;

Figure 9 is an end elevation of the work spindle and support, with parts broken away;

Figure 11 is a fragmentary perspective of the grinding machine illustrating the arrangement thereof for performing a different grinding operation; and

Figure 12 is a fragmentary perspective of the grinding machine illustrating the arrangement thereof for performing still another grinding operation.

Referring first to Figure 1, the grinding machine comprises a, base l0 which is a heavy, rigid casting, an intermediate work table II which is mounted for horizontal adjustment from front to back of the machine, a work slide l2 mounted on the intermediate table II for traverse from side to side, and a tool or grinding wheel support l3 which is adjustable, as will later be de-' scribed.

Adjustment of the intermediate table H from front to back is accomplished by handwheels through conventional gearing. and traverse of the work slide l2 from right to left is likewise accomplished by conventional transmission means connected to a handwheel.

Referring now to Figures 2 to 4, we illustrate in Figure 2 a vertical section through the support for the tool spindle. Formed in the frame of the machine I0 is a, cylindrical recess or well I5,

.is bolted or otherwise secured, as indicated at 20, a member 2| provided with an internal cylindrical bore 22, nd adapted to have at its upper portion a nut 23 bolted or otherwise secured thereto as indicated at 24. A supporting casting indicated generally at 25 has a lower cylindrical portion 26 received in slidable relation within member l6 and an upper reduced cylindrical portion 21 slidably received within portion I5 of the frame. A web 28 having a centrally apertured boss 29 is provided in the casting 25. A vertical feed screw 30 extends through the boss 29. Beneath the boss 29 the feed screw is shouldered as indicated at 3i, and intermediate the shoulder 3| and the boss 29 is a bearing 32. The weight of the casting 25 and mechanism supported thereby is received on the shoulder 3i, and vertical adjustment of the screw 30 is transmitted to the casting 25 and the parts supported thereby. The lower portion of the screw 30 is threaded as indicated at 83 and is received in threaded relation within the nut 23.

Secured on the upper reduced portion of the screw 38 is a bevel gear 85, keyed or otherwise secured to the screw 88 as indicated at 88. Bevel gear 85 is retained against longitudinal displacement on the screw 38 by means of a nut 31.

Casting 25 has a lateral opening 48 adapted to receive a block 4| which is bored to receive a shaft 42. Shaft 42 carries at its inner end a bevel gear 49 meshing with the bevel gear 85 previously described, and at its outer end is provided with a handwheel 44. Rotation of the handwheel 44 results in a corresponding rotation of the screw 88 and as a result of threaded relation between the lower end 01' the screw and the nut 23, this results in vertical movement of the casting 25 and associated parts.

The casting 25, in addition to being vertically adjustable in the frame portion I5, is also angularly adjustable about a vertical axis therein. At the upper portion of the well I is provided a collar 48 having a set screw 49 adapted to engage a keyway in the casting 25 and to hold the same against rotation within the well I5. The collar 48 is provided with an opening 58 through which the outer wall of the well I5 is visible, and if desired suitable graduations indicated at 5| may be located on the outer wall 01' the well I5 for cooperation with a similar index mark 52 in the opening 58. This will indicate the angular adlustment of the casting 25.

The casting 25 is provided with a pair of opposed plates 55 provided with central trunnion bearings 56 in which is mounted a split sleeve 51 which is adapted to clamp a spindle housing 58 for a grinder. Spindle housing 58 is connected to and supports a drive motor 59 at one end, which drives a grinding wheel 88 by means of a spindle extending through the spindle housing 58.

The sleeve 51 is provided at diametrically opposite sides with a pair of pins 83 adapted to be received within trunnion bearings 58 and to support the sleeve 51 in the bearings.- Spaced from pins 63 in the sleeve 51 are a pair 01' diametrically opposed tapped openings for the reception of clamping bolts 62. The plates 55 are each provided with a pair of arcuate slots 84 through which are adapted to pass the clamping bolts 82 previously referred to. As seen in Fig. ures 3 and 4, the pins 88 are located adiacent one end of the sleeve 51, and the arrangement is such that when the sleeve is reversed or swung through an arc of 180 about the pivot axis determined by the pins 83, the tapped openings previously referred to, for the reception of clamping bolts 82, will be aligned with the other oi the arcuate slots 84. This results in a substantial displacement in a direction perpendicular to the axis of the casting 25. In addition, as will be appreciated, the grinding wheel 88 may be adsecured to the base 14 for adjustment about a vertical axis established by adowel pin 18 passing through a central opening at the bottom of the bracket 15 and seated within a similar recess indicated at 11 in the base 14. Clamping bolts 18 have heads 19 received within circular ways indicated at 88 and are adapted to clamp the bracket 15 in any position of adjustment.

The tool spindle 1| includes a main casting 8| provided with depending ears 82. A trunnion connection between the bracket 15 and the casting 8| is established by means or a bolt 85 pass ing through an opening in one of the arms of the yoke 15 and extending into a corresponding opening in one of the ears 82. The bolt 85 is adapted to be locked in position by means of a set screw indicated at 88. The opposite pivot point or the trunnion connection is established by means of a sleeve 81, the sleeve 81 being provided for the passage of a tape, later to be described. In order to lock the spindle assembly 1| in any position of adjustment about the axis of the trunnion connection just described, arcuate slots 88 are provided in the depending ears 82 and are adapted to receive locking bolts 89 passing through openings in the arms of the yoke 15.

The spindle assembly 1| is best seen in Figure 10, to which reference is now made. The main casting 8|, of which the depending ears 82 are a part, is centrally bored to receive the component parts of the spindle assembly in assembled relation.

The spindle proper is designated by the numeral 98 and is provided with a radially extending flange 9| The spindle 98 is centrally bored, as indicated at 92, for the reception of a locking rod 93 which is longitudinally slidable therein. The rod 93, at one end, is provided with a nut 94, threaded thereon and clamped in assembled position by means of a set screw 95. The righthand end of the spindle 98, as seen in Figure 18, is reduced, as indicated at 98, and a flanged sleeve 91 is slidable thereon. The flanged sleeve 91 is illustrated in Figure 10 as provided with annular spacers 98 and 99, and the work piece I88 is clamped thereon, a washer I8| being urged against the work piece I88 by means of a clamping nut I82. This locks the work piece I88 rigidly on the sleeve 91.

The sleeve 91 has bolted or otherwise secured thereto an index member or gear I 85 which is adapted to cooperate with an index finger I88 shown in Figure 9. The index finger I88 is slidably retained within an index housing I81 which is bolted to the spindle flange 9| as indicated at I88. The housing I81 is closed at its outboard end by means of a plate II 8 and is provided with 7 an elongated slot I through which passes an justed horizontally in a direction parallel to the axis by adjustment of the spindle housing 58 in the sleeve 51. The reversibility of the sleeve 51 referred to extends the range of adjustment obtainable a considerable degree.

Referring now particularly to Figures 5, 9 and 10, we have indicated at 18 adjustable supporting means for the work spindle comprising a base plate 14 and a U-shaped bracket 15. The base plate 14 is adapted to be bolted or otherwise rigidly clamped as indicated at 12 in ways 13 formed in a portion of the work slide I2, as seen in Figure 1, and the U-shaped bracket or yoke 15 is operating finger |I2 rigidly secured to the index finger I86. A compression spring 3 seats in a recess of the plate I I8 and a corresponding recess of the index finger I88 and urges the finger into a tooth space of the index plate I85.

In order to position the index finger I88 positively against transverse displacement, we provide an adjustable plate 4 in the index housing 81. A pin II5 retains the plate 4 against longitudinal movement and the plate 4 may be adjusted into guiding contact with the index finger I86 by bolts H6.

The index plate I and the flanged sleeve 81 are mounted for rotation on the spindle 98, the index plate I85 being in juxtaposition to the flange 9|. Means are provided for clamping the index plate I85 against the flange 91 in order to prevent relative rotation between the spindle 30 and the work piece I00. Referring specifically to Figure 10, the locking rod 93 is urged to the right. as seen in Figure 10, by means of a compression spring I20, thus tending to prevent clamping or looking engagement between the index plate I05 and the flange At the opposite end of the locking rod 93 we secure a member I2I to which is pivoted a locking lever I22 which has a cumming surface I23 engageable with a plate I24 set within a recess at the end of the spindle 30. When the lever I22 is swung in a counterclockwise direction, as seen in this figure, it urges the locking rod 93 to the left and moves the sleeve 91 and the index plate I to the left relative to spindle 00. This produces tight frictional contact between-the flange III of the spindle and the index plate I05, thus securing the parts together to prevent independent rotation.

Mounted on the spindle 90 and keyed thereto as indicated at I25 is a second sleeve I26. Intermediate the sleeve I26 and the spindle casting 8| are bearings indicated at I21. In order to prevent ingress of dust to the bearings I21 we provide a plurality of hardened rings I28 which are urged into contact with sealing rings I30 by means of springs I3I.

The second sleeve I26, previously referred to, has keyed or otherwise secured thereto, as indicated at I35, a enerating roll I36 to which is secured a tape I31, later to be described.

It will be observed that rotation imparted to the generating roll I36 by the tape I31 is transmitted to the second sleeve I26 by means-of key I35 and is transmitted to the spindle 90 by means of key I25. If the lever I22 is in clamping position, rotation of the generating roll I36 will be imparted directly to the work piece I00. At this time. if the clamping lever I22 is in released position but the index fin er I06 is engaged with the index plate I 05, rotation of the generating roll I36 will likewise be effective to rotate the work piece IM.

A set screw IE0 is threaded within the spindle casting SI and is adapted to engage the base roll 36 or the tape I31 to lock the spindle Q0 against rotation relative to the spindle casting 8i Referring now particularly to Figure 9, we have indicated the tape It? as secured to the generating roll I35 at I50. The other end of the tape I3! is connected to a plunger IEI by means of a swivel connection indicated generally at Hit, the swivel connection including ball bearings I53, permitting relative swiveling motion between the swivel connection I52 and the plunger I5 I.

Referring now more particularly to Figures 5 and 9, a bracket I55 is bolted to one of the arms of the yoke 15 by the bolt 89 and by additional securing means I56. The bracket I55 includes an overarm I51 which is open along its underside to carry ball-bearing receiving ways indicated at I58, as seen in Figure 5. Slidable in the ways I53 is a carriage I62 which is provided with a depending roller I 80 mounted for free rotation an adjusting nut I having a knurled grip I66.

The nut I55 is threaded over a portion I61 of the 7 plunger IiiI. If the roller I60 is retained stationary, adjustment of the nut I65 will cause adJust-' ment of the tape I31 relative thereto, thus imparting rotation to the generating roll I36 and associated parts. As will be appreciated, this is a line adjustment for bringing a work piece carried by the spindle into proper relationship with the grinding wheel.

Referring again to Figure 10, spring means are provided for constantly biasing the spindle 90 in one direction or the other. This means takes the form of a coil spring of the phonograph type, indicated generally at I10. The spring proper IN is secured at one end to a hub I12.which is keyed or otherwise secured to the spindle 90, as indicated at I13. The other end of the spring "I is locked to a two-piece housing I14 by means of a pin I15. A locking member I16 having a pin I11 engaging in a recess in the spindle casting BI is adapted to be clamped into locking engagement with the housing I14 by means of a bolt I18. In order to wind or tension the spring I1 I, clamping member I16 is released and the housing portion I14 is rotated in the proper direction to tension the spring, after which the locking member I16 is again tightened. The housing I14 of the spring is reversible so that by removing the same from the spindle 90 and reversing the same, tension may be applied to the spindle in either direction.

A sine bar arrangement is provided for rotating the spindle 90, this arrangement including the roller I60 and other structure illustrated in detail in Figures 6 to 8.

Referring to these figures, a bracket I is bolted or otherwise secured to the intermediate support II by bolts WI. The bracket I80 has a groove I82 in its upper surface for the reception of a bar I83, the bar I83 being retained in the groove in by means of overhanging strips IB I bolted to the bracket I00 by bolts I85.

Adjacent the inboard end of the bar I03 is a dowel pin I86 threaded into the bar I83 as indicated at I87 and locked in position therein by means of a set screw I88. Dowelpin I86 establishes a pivot connection for a swivel plate I90. having bolted or otherwise secured thereto as indicated at IQI a sine bar I92. sine bar I92 has an accurately machined surface I93 adapted to be engaged by the roller-I60 previously referred to. Swivel plate I00 is provided with a radially extending flange I95 adapted to be received beneath an arcuate clamping member 596. By releasing the clamping member I96 the swivel plate I00 may be adjusted about the pivot axis of the dowel pin I86 to position the sine bar I92 at .he desired angle. As best seen in Figure 6, the clamping member its is provided with an index mark I91 which is adapted to cooperate with indicia I98 formed on the swivel plate I to indicate the angularity of adjustment of the swivel plate and sine bar.

The apparatus described may be employed for a number of diiferent operations and is so flexible that it is adaptable to perform all of the grindin operations necessary on the complete grinding of milling cutters, either cylindrical or conical, and having straight or helical teeth. By means of the apparatus described, it will also be possible to provide helical teeth on cylindrical or conical cutters in which the tops of the teeth are relieved in a helical path identical with the helical cutting edge of the teeth so that if desired a narrow land of absolute uniform width may be left directly at the rear of the cutting edge. 7

It has been found that for certain types of machining and more particularly for a machining operation known as surface shaving, it is desirable to provide milling cutters having helical the cutting edge. So far as we are aware, the present machine is the only one available for performing this operation, either in the manufacture of new cutters or in the resharpening of used cutters.

In Figures 11 and 12 we have illustrated two different set-ups. In Figure 11 we illustrate a work piece 200, and the operation being performed is the grinding of the sides of straight teeth 20L For this purpose the work spindle assembly H has been adjusted so that its axis extends upwardly at such an angle that the side surfaces of the teeth 20] extend horizontally. The axis of the grinding wheel 80 is horizontal and has been adjusted around a vertical axis to conform to the work. Since the operation illustrated is the grinding of straight teeth, the generating sine bar attachment has been disconnected and the work spindle 90 has been locked in adjusted position by tightening the bolt H illustrated in Figure 10. To perform the grinding operation, the slide i2 is reciprocated in the direction of the arrow 202.

In Figure 12 we have illustrated a different arrangement for grinding helical teeth 205 of a bevel cutter 206. In this'case, in order to generate helical teeth, it is necessary to connect up the sine :bar mechanism, and in this figure we have illustrated the roll "50 as in contact with the sine bar I92. In this case clamping bolt I40 (Figure 10) has been released and the spindle 80 is connected to drive the work piece -206 through the indexing mechanism, including the index plate 9| and the index finger I06 (Figure 9). The work spindle assembly H is adjusted around so that the tooth surfaces being worked on will pass in a horizontal plane relative to the grinding wheel 60, due to the generating roll imparted to the work piece 205. The grinding operation comprises reciprocating the work piece in the direction of the arrow 201, which will result in moving the work piece past the grinding wheel 60 with a generating roll imparted there-.

to through the medium of the tape 1 31.

Referring now to Figure 1, attention is directed to an important feature of novelty of the present apparatus. The grinder 60 is mounted for angular adjustment in the support l3 about the axis of trunnion bearings 56. Mounted directly upon the tool spindle support 58 is a trimmer fixture indicated generally at 2:0. This trimmer support is mounted for vertical adjustment relative to the axis of the-grinder 60 on posts 2| I, and the trimming mechanism is adjustable on arms 2l2. Trimmer points are carried by blocks 2|3 so that the wheel may be trimmed when necessary without traversing trimming mechanism to the grinding zone as is present practice today. This facilitates trimming of the wheel and expedites the whole grinding process. It will be appreciated, of course, that after trimming the wheel the same will be fed downwardly, as for example by suitable adjustment by means of the handwheel 44 in Figure 2 to retain the desired relationship between the wheel and the work.

The present machine may be employed to manufacture a milling cutter of the type referred to from a tool blank, or it may be employed to finish grind a cutter previously milled to approximate dimensions. The operations involve grinding the periphery of the cutter to establish concentricity, after which the teeth may be gummed out, or if previously. milled, may be finished ground.

cutting edge and finishes the tooth spaces. It leaves a substantially unrelieved land directly in back of the cutting edge. By employing the present'machine, this land back of the cutting edge may be relieved to any extent desired, this relief being provided in a helical path where the cutter teeth are helical. It is possible to relieve the tops of the cutter teeth in such a'manner as to leave a narrow unrelieved land directly in back of the cutting edge, which will be uniform from end to end. This may also be done in resharpening cutter teeth. The same machine is adaptable for manufacturing or finish grinding cylindrical or conical cutters, either of which may have either straight or inclined, or helical teeth, as desired.

While we have illustrated and described a specific grinding machine, it will be understood that this has been done merely to enable those skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

1. A grinder comprising a base, a column vertically adjustable on said :base, a' yoke mounted on said column for adjustment about a vertical axis, and a grinding wheel and drive means therefor swiveled between the arms of said yoke for adjustment about a horizontal axis, a slide on said base adjustable toward and away from said column, a bracket mounted on said slide for adjustment about a vertical axis, a work spindle mounted on said bracket for adjustment about a horizontal axis, means for translating said slide in a direction perpendicular to its aforementioned adjustment, and means responsive to translation of said slide for rotating said spindle.

2. A grinder comprising a base, a colunm vertically adjustable on said base, a yoke mounted on said column for adjustment about a vertical axis, and a grinding wheel and drive means therefor swiveled between the arms of said yoke for adjustment about a horizontal axis, a slide on said base adjustable toward and away from said column, a bracket mounted on said slide for adiustment about a vertical axis, a work spindle mounted on said bracket for adjustment about a horizontal axis, means for translating said slide in a direction perpendicular to its aforementioned adjustment, and means responsive to translation of said slide for rotating said spindle, said means comprising a sine bar carried by said frame, a roll connected to said spindle, and a tape secured to said roll and operated by said sine bar.

3. In a machine of the character described, a frame, a sine bar on said frame, a spindle support mounted for rectilinear traverse on said Y frame, a rotary spindle therein, an arm extending This operation establishes the hook in front of the 76 from said support toward said sine bar, ways in said arm, a member slidably mounted in said ways, a roller carried by said member engageable with said sine bar, a roll connected to said spindle, and a tape one end of which is adlustably connected to said member, the other end of said tape extending partly around said roll and secured thereto, said one end of said tape being connected to said member for adjustment relative thereto in a direction parallel to the direction of sliding of said member.

4. In a machine of the character described, a spindle having a roll secured thereto, a support for said spindle having a portion providing ways extending perpendicular to said spindle, a sine bar located adjacent said ways, a member slidable in said ways having a part engageable with said sine bar, a threaded element slidably associated with said member, a nut for said element operable to adjust said element longitudinally of said member, a tape secured to said element at one end, the other end of said tape being extended partly around said roll and secured there,- to.

5. In a machine of the character described, a frame, a spindle having a generating roll secured thereto, a spindle support mounting said spindle on said frame for adjusting said spindle an axis perpendicular to the spindle axis and substantially tangent to said roll, a tape having an end portion wound partly around said roll and secured thereto and having its opposite end portion extending substantially along the axis of adjustment of said spindle support, and means for moving said tape longitudinally to effect rotation of said spindle.

6. In a machine of the character described, a frame, a spindle having a generating roll secured thereto, a spindle support mounting said spindle on said frame for adjusting said spindle about an axis perpendicular to the spindle axis and substantially tangent to said roll, a tape having an end portion wound partly around said roll and secured thereto and having its opposite end portion extending substantially along the axis of adjustment of said spindle support, a member relatively movable toward and away from said spindle along said last mentioned axis, and a swivel connection between said member and the said other end of said tape.

7. In a. machine of the character described, a frame, a spindle having a generating roll secured thereto, a spindle support mounting said spindle on said frame for adjusting said spindle about substantially tangent to said roll, a tape having an end portion wound partly around said roll and secured thereto and having its opposite end portion extending substantially along the axis of adjustment of said spindle support, a guideway extending substantially along said last mentioned axis, a member slidable in said guideway toward and away from said roll, an element adjustable longitudinally of said member, and a swivel connection between said element and the other end of said tape.

8. In a machine of the character described, a frame, a spindle having a generating roll secured thereto, a spindle support mounting said spindle on said frame for adjusting said spindle about an axis perpendicular .to the spindle axis and substantially tangent to said roll, a tape having an end portion wound partly around said roll and secured thereto and having its opposite end portion extending substantially along the axis of adjustment of said spindle support, a guideway extending substantially along said last mentioned axis, a. member slidable in said guideway toward and away from said roll, an element adjustable longitudinally of said member, a swivel connection between said element and the other end of said tape, a sine bar on said frame, said member having a portion engageable with said sine bar, and means for relatively traversing said sine bar and support to effect rotation of said spindle.

9. In a machine of the character described, a spindle having a generating roll secured thereto, a support for said spindle, a spring housing having a core keyed to said spindle and an outer shell locked to said support, a coil spring in said shell surrounding said core and connected at its ends to said core and shell.

Ii). In a machine of the character described, a

, an axis perpendicular to the spindle axis and spindle having a generating roll secured thereto, a support for said spindle, a spring housing having a core keyed to said spindle and an outer shell looked to said support, a coil spring in said shell surrounding said core and connected at its ends to said core and shell, said outer shell and said support having interfltting portions, a clamp carried by said support and arranged to interlock said shell and said support by applying pressure between said interfitting portions.

11. In a machine of the character described, a spindle having a generating roll secured thereto, a support for said spindle, an index plate and work support mounted for rotation on said spindle, indexing means mounted on said spindle including an index finger cooperable with said plate, and releasable clamping means carried by said spindle for locking said index plate to said spindle, said spindle being hollow, and said clamping means comprising a rod extending through said spindle having an abutment at one end engageable with said index plate and work support, said spindle having a radial flange adjacent said index plate and work support, and camming means at the other end of said rod for moving said rod axially of said spindle to apply frictional clamping pressure between said index plate and work support and said radial flange.

12. A universal grinding machine comprising a frame, a grinder support on said frame mounted for vertical adjustment and for, adjustment about a vertical axis, a grinding wheel on said support mounted for adjustment about a horizontal axis, a work slide on said frame adjustable horizontally toward and away from said grinder support, and mounted for operating traverse horizontally in a direction perpendicular to the direction of its horizontal adjustment, a work spindle bracket mounted on said slide for adjustment about a horizontal axis perpendicular to the axis of said spindle, a spindle in said bracket having a generating roll secured thereto, the periphery of said generating roll being tangent to the axis of adjustment of said bracket, a sine bar on said frame mounted for adjustment toward and away from said work slide and adjustable about a vertical axis to vary its inclination to the path of traverse of said slide, means carried by said slide movable toward and away from said spindle along the axis of adjustment of said bracket operatively engaging said roll in various positions of adjustment of said bracket and engaging said sine bar.

13. A universal grinding machine comprising a frame, a grinder support on said frame mounted for vertical adjustment and for adjustment about a vertical axis, a grinding wheel on said support mounted for adjustment about a horizontal axis, a work slide on said frame adjustable horizontally toward and away from said grinder support, and mounted for operating traverse horizontally in a direction perpendicular to'the direction of its horizontal adjustment, a work spindle bracket mounted on said slide for adjustment about a horizontal axis perpendicular to the axis of said spindle, a spindle in said bracket having a generating roll secured thereto, the periphery of said generating roll being tangent to the axis of adjustment of said bracket, a sine bar on said frame mounted for adjustment toward and away from said work slide and adjustable about a vertical axis to vary its inclination to the path of traverse of said slide, means carried by said slide movable toward and away from said spindle along the axis of. ad-

justment of said bracket operatively engaging said roll in various positions of adjustment of said bracket and engaging said sine bar, said means comprising a member having a portion engaging said sine bar, and a tape interconnecting said member and said roll.

14. A universal grinding machine comprising a frame, a grinder support on said frame mounted for vertical adjustment and for adjustment about a vertical axis, a grinding wheel on said support mounted for adjustment about a horizontal axis, a work slide on said frame adjustable horizontally toward and away from said grinder support, and mounted for operating traverse horizontally in a direction perpendicular to the direction of its horizontal adjustment, a work spindle bracket mounted on said slide for adjustment about a horizontal axis perpendicular to the axis of said spindle, a spindle in said bracket having a generating roll secured thereto, the periphery of said generating roll being tangent to the axis of adjustment of said bracket, a sine bar on said frame mounted for acUustment toward and away from said work slide and adjustable about a vertical axis to vary its inclination to the path of traverse of said slide, means carried by said slide movable toward and away from said spindle along the axis of adjustment 0! said bracket operatively enga ing said roll in various positions of adjustment of said bracket and engaging said sine bar, said means comprising a member having a portion engaging said sine bar, and a tape swiveled to and longitudinally adjustable relative to said member, and connected at its other end to said roll.

15. In a machine of the character described, a spindle housing, a spindle mounted for rotation therein, a radial flange on said spindle, a support rotatably mounted on said spindle adjacent said flange, an index plate rigidly secured to said support. and a spring-pressed index finger carried by said flange and positioned to cooperate with recesses in said index plate.

16. In a machine oi the character described. a spindle housing, a spindle mounted for rotation therein, a generating roll keyed to said spindle, a tape extending partly around said roll and secured thereto, means for moving said tape relative to said roll along a line of action tangential to said roll to impart rotation to said spindle, and supporting means mounting said spindle housing for pivotal adjustment about an axis substantial- 1y coincident with said line of action.

17. In a machine or the character described, a spindle housing, a spindle mounted for rotation therein, a generating roll keyed to said spindle, a tape extending partly around said roll and secured thereto, means for moving said tape rela tive to said roll along a line or action tangential to said roll to impart rotation to said spindle, said last means comprising a sine bar device including a member movable along said line oi action, a swivel connection between said member and said tape, and supporting means mounting said spindle housing for pivotal adjustment about an axis substantially coincident with said line or action.

18. In a machine of the character described, a spindle having a generating roll secured thereto, tape means ior controlling rotation of said spindle, a support for said spindle, a phonographtype spring secured at one end to said spindle, a case for said spring to which the other end of said spring is secured, and releasabl means for securing said case against rotation relative to said support.

MAX B. MEN'I'LEY. DONALD D. AUSTIN. 

